Optical properties of normal and cancerous human skin in the visible and near-infrared spectral range

Abstract

Differences in absorption and/or scattering of cancerous and normal skin have the potential to provide a basis for noninvasive cancer detection. In this study, we have determined and compared the in vitro optical properties of human epidermis, dermis, and subcutaneous fat with those of nonmelanoma skin cancers in the spectral range from 370 to 1600 nm. Fresh specimens of normal and cancerous human skin were obtained from surgeries. The samples were rinsed in saline solution and sectioned. Diffuse reflectance and total transmittance were measured using an integrating sphere spectrophotometer. Absorption and reduced scattering coefficients were calculated from the measured quantities using an inverse Monte Carlo technique. The differences between optical properties of each normal tissue-cancer pair were statistically analyzed. The results indicate that there are significant differences in the scattering of cancerous and healthy tissues in the spectral range from 1050 to 1400 nm. In this spectral region, the scattering of cancerous lesions is consistently lower than that of normal tissues, whereas absorption does not differ significantly, with the exception of nodular basal cell carcinomas (BCC). Nodular BCCs exhibit significantly lower absorption as compared to normal skin. Therefore, the spectral range between 1050 and 1400 nm appears to be optimal for nonmelanoma skin cancer detection.

Light transmittance of the periodontium

“…The attenuation coefficients calculated in this study were lower than the equivalent attenuation coefficients of skulls [44,45] and skin [46,47] reported in previous studies. The discrepancies may be attributed to the difference in experimental design including selection of light source and detector, experimental setup, and the materials and sample preparation.…”

Predictive analysis of photodynamic treatment depth with different photosensitizer based nanocarriers

“…Se consideraron NPs esféricas de radios 40 nm y 80 nm, así como dos concentraciones (2·10 9 y 4·10 9 cm -3 ) distribuidas homogéneamente en un carcinoma basocelular nodular de 6 mm de profundidad. Las propiedades ópticas de este tipo de tejido tumoral fueron obtenidas a la longitud de onda de interés (coincidente con el valor central de los rangos de absorción máxima anteriormente referidos) para excitar las diferentes moléculas de fotosensibilizador y desencadenar las reacciones fotoquímicas a partir de las cuales se produce el agente citotóxico encargado de la destrucción del tejido durante la TFD [13].…”

Расчет Передаточных Функций Многослойных Биотканей В Задачах Коррекции Их Спектров Флуоресценции

“…Для моделирования спектральных зависимостей показа-телей µ a и µ ′ s жировой клетчатки используются данные работы [51]. Средний косинус индикатрисы рассеяния g всех слоев кожи рассчитывается по эмпирической фор-муле: g = 0.62 + 0.29λ · 10 −3 [52], где λ выражена в nm.…”